diff --git a/libcrux-ml-kem/cg/eurydice_glue.h b/libcrux-ml-kem/cg/eurydice_glue.h
index bc07ba4b9..cdd27af77 100644
--- a/libcrux-ml-kem/cg/eurydice_glue.h
+++ b/libcrux-ml-kem/cg/eurydice_glue.h
@@ -164,7 +164,7 @@ static inline uint8_t core_num__u8_6__wrapping_sub(uint8_t x, uint8_t y) {
 
 #define Eurydice_range_iter_next(iter_ptr, t, ret_t) \
   (((iter_ptr)->start == (iter_ptr)->end)            \
-       ? (CLITERAL(ret_t){.tag = None})              \
+       ? (CLITERAL(ret_t){.tag = None, .f0 = 0})     \
        : (CLITERAL(ret_t){.tag = Some, .f0 = (iter_ptr)->start++}))
 
 #define core_iter_range___core__iter__traits__iterator__Iterator_for_core__ops__range__Range_A__TraitClause_0___6__next \
diff --git a/libcrux-ml-kem/cg/fuzz/.gitignore b/libcrux-ml-kem/cg/fuzz/.gitignore
new file mode 100644
index 000000000..d28f1baa8
--- /dev/null
+++ b/libcrux-ml-kem/cg/fuzz/.gitignore
@@ -0,0 +1,5 @@
+dec_fuzz
+enc_fuzz
+mkcorpus
+valid_fuzz
+*.o
diff --git a/libcrux-ml-kem/cg/fuzz/Makefile b/libcrux-ml-kem/cg/fuzz/Makefile
new file mode 100644
index 000000000..bf98a1b02
--- /dev/null
+++ b/libcrux-ml-kem/cg/fuzz/Makefile
@@ -0,0 +1,35 @@
+CC=clang-18
+CXX=clang++-18
+FUZZ_FLAGS=-fsanitize=address,undefined,fuzzer -fno-omit-frame-pointer
+FUZZ_LIBS=-L/usr/lib/llvm-18/lib -lFuzzer
+
+CXXFLAGS=-O2 -g -Wall -Wextra -Wno-unused-parameter -Wno-exceptions -I..
+CFLAGS=$(CXXFLAGS)
+LDFLAGS=-g
+LIBS=
+COMMON_DEPS=
+
+TARGETS=enc_fuzz valid_fuzz dec_fuzz mkcorpus
+
+all: $(TARGETS)
+
+.cc.o:
+	$(CXX) $(CXXFLAGS) $(FUZZ_FLAGS) -c $< -o $@
+
+.c.o:
+	$(CC) $(CFLAGS) -c $< -o $@
+
+enc_fuzz: enc_fuzz.o $(COMMON_DEPS)
+	$(CXX) -o $@ enc_fuzz.o $(LDFLAGS) $(LIBS) $(FUZZ_FLAGS) $(FUZZ_LIBS)
+
+dec_fuzz: dec_fuzz.o $(COMMON_DEPS)
+	$(CXX) -o $@ dec_fuzz.o $(LDFLAGS) $(LIBS) $(FUZZ_FLAGS) $(FUZZ_LIBS)
+
+valid_fuzz: valid_fuzz.o $(COMMON_DEPS)
+	$(CXX) -o $@ valid_fuzz.o $(LDFLAGS) $(LIBS) $(FUZZ_FLAGS) $(FUZZ_LIBS)
+
+mkcorpus: mkcorpus.o
+	$(CC) -o $@ mkcorpus.o
+
+clean:
+	-rm -f *.o $(TARGETS)
diff --git a/libcrux-ml-kem/cg/fuzz/dec_fuzz.cc b/libcrux-ml-kem/cg/fuzz/dec_fuzz.cc
new file mode 100644
index 000000000..f6b35097d
--- /dev/null
+++ b/libcrux-ml-kem/cg/fuzz/dec_fuzz.cc
@@ -0,0 +1,52 @@
+// Basic fuzz test for depcapsulate operation,
+
+#include <stddef.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "libcrux_mlkem768_portable.h"
+
+extern "C"
+{
+
+	void privkeys(libcrux_ml_kem_types_MlKemPrivateKey_55 *zero_sk,
+				  libcrux_ml_kem_types_MlKemPrivateKey_55 *rnd_sk)
+	{
+		uint8_t rnd[64];
+		memset(rnd, 0, sizeof(rnd));
+		auto kp = libcrux_ml_kem_mlkem768_portable_kyber_generate_key_pair(rnd);
+		*zero_sk = kp.sk;
+		(void)getentropy(rnd, sizeof(rnd));
+		kp = libcrux_ml_kem_mlkem768_portable_kyber_generate_key_pair(rnd);
+		*rnd_sk = kp.sk;
+	}
+
+	int LLVMFuzzerTestOneInput(const uint8_t *input, size_t len)
+	{
+		static bool once;
+		uint8_t ret[32];
+		libcrux_ml_kem_types_MlKemPrivateKey_55 zero_sk, rnd_sk;
+		libcrux_ml_kem_mlkem768_MlKem768Ciphertext ct;
+
+		if (!once)
+		{
+			privkeys(&zero_sk, &rnd_sk);
+			once = true;
+		}
+
+		memset(&ct, 0, sizeof(ct));
+		if (len > sizeof(ct.value))
+		{
+			len = sizeof(ct.value);
+		}
+		memcpy(ct.value, input, len);
+
+		libcrux_ml_kem_mlkem768_portable_decapsulate(&zero_sk, &ct, ret);
+		libcrux_ml_kem_mlkem768_portable_decapsulate(&rnd_sk, &ct, ret);
+		return 0;
+	}
+
+} // extern
diff --git a/libcrux-ml-kem/cg/fuzz/enc_fuzz.cc b/libcrux-ml-kem/cg/fuzz/enc_fuzz.cc
new file mode 100644
index 000000000..1cf5f9d2c
--- /dev/null
+++ b/libcrux-ml-kem/cg/fuzz/enc_fuzz.cc
@@ -0,0 +1,34 @@
+// Basic fuzz test for encapsulate operation.
+
+#include <stddef.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "libcrux_mlkem768_portable.h"
+
+extern "C"
+{
+
+	int LLVMFuzzerTestOneInput(const uint8_t *input, size_t len)
+	{
+		uint8_t rnd[32];
+		libcrux_ml_kem_mlkem768_MlKem768PublicKey pk;
+
+		memset(rnd, 0, sizeof(rnd));
+		memset(&pk, 0, sizeof(pk));
+		if (len > sizeof(pk.value))
+		{
+			len = sizeof(pk.value);
+		}
+		memcpy(pk.value, input, len);
+
+		(void)libcrux_ml_kem_mlkem768_portable_encapsulate(&pk, rnd);
+		(void)getentropy(rnd, sizeof(rnd));
+		(void)libcrux_ml_kem_mlkem768_portable_encapsulate(&pk, rnd);
+		return 0;
+	}
+
+} // extern
diff --git a/libcrux-ml-kem/cg/fuzz/mkcorpus.c b/libcrux-ml-kem/cg/fuzz/mkcorpus.c
new file mode 100644
index 000000000..b681e2fb3
--- /dev/null
+++ b/libcrux-ml-kem/cg/fuzz/mkcorpus.c
@@ -0,0 +1,65 @@
+// Makes basic seed corpora for other fuzzers
+//
+// Will write to ./pubkey_corpus (for valid_fuzz and enc_fuzz) and
+// to ./ciphertext_corpus (for dec_fuzz)
+
+#include <err.h>
+#include <errno.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "libcrux_mlkem768_portable.h"
+
+#define NSEEDS 1000
+
+void write_blob(const char *path, int n, const char *suffix, const void *p,
+                size_t l) {
+  char name[256];
+  FILE *f;
+
+  snprintf(name, sizeof(name), "%s/%06d.%s", path, n, suffix);
+  if ((f = fopen(name, "wb+")) == NULL) {
+    err(1, "fopen %s", name);
+  }
+  if (fwrite(p, l, 1, f) != 1) {
+    err(1, "write %s", name);
+  }
+  fclose(f);
+}
+
+int main(void) {
+  int i;
+  uint8_t rnd[64];
+  libcrux_ml_kem_mlkem768_MlKem768KeyPair kp;
+  tuple_3c enc;
+
+  if (mkdir("pubkey_corpus", 0777) != 0 && errno != EEXIST)
+    err(1, "mkdir pubkey_corpus");
+  if (mkdir("ciphertext_corpus", 0777) != 0 && errno != EEXIST)
+    err(1, "mkdir ciphertext_corpus");
+
+  for (i = 0; i < NSEEDS; i++) {
+    if (i == 0) {
+      memset(rnd, 0, sizeof(rnd));
+    } else {
+      (void)getentropy(rnd, sizeof(rnd));
+    }
+    kp = libcrux_ml_kem_mlkem768_portable_kyber_generate_key_pair(rnd);
+    write_blob("pubkey_corpus", i, "pk", kp.pk.value, sizeof(kp.pk.value));
+
+    if (i == 0) {
+      memset(rnd, 0, sizeof(rnd));
+    } else {
+      (void)getentropy(rnd, sizeof(rnd));
+    }
+    enc = libcrux_ml_kem_mlkem768_portable_encapsulate(&kp.pk, rnd);
+    write_blob("ciphertext_corpus", i, "ct", enc.fst.value,
+               sizeof(enc.fst.value));
+  }
+  return 0;
+}
diff --git a/libcrux-ml-kem/cg/fuzz/valid_fuzz.cc b/libcrux-ml-kem/cg/fuzz/valid_fuzz.cc
new file mode 100644
index 000000000..44c34945b
--- /dev/null
+++ b/libcrux-ml-kem/cg/fuzz/valid_fuzz.cc
@@ -0,0 +1,32 @@
+// Basic fuzz test for pubkey validation.
+
+#include <stddef.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "libcrux_mlkem768_portable.h"
+
+extern "C"
+{
+
+	int LLVMFuzzerTestOneInput(const uint8_t *input, size_t len)
+	{
+		uint8_t rnd[32];
+		libcrux_ml_kem_mlkem768_MlKem768PublicKey pk;
+
+		memset(rnd, 0, sizeof(rnd));
+		memset(&pk, 0, sizeof(pk));
+		if (len > sizeof(pk.value))
+		{
+			len = sizeof(pk.value);
+		}
+		memcpy(pk.value, input, len);
+
+		(void)libcrux_ml_kem_mlkem768_portable_validate_public_key(&pk);
+		return 0;
+	}
+
+} // extern